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CIRCUIT CLOSING ATTACHMENT FOR PRESSURE GAGES. N0. 339,094. 7 fatented Mar. 30, 1886.

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UNITED STATES PATENT Orrica,

MILTON V. GROVESTEEN, OF NElV YORK, N, Y.

CIRCUIT-CLOSING ATTACHMENT FOR PRESSURE-GAGES.

SPESIFICATION forming part of Letters Patent No. 339,094, dated March 30, 1886.

Application filed December 1'7, 1885. Serial No. 186,002.

To all whom it may concern:

Be it known that I, MILTON W. GROVE sTEEN, a citizen of the United States, residing in the city of New York, in the county and State of New York, have invented certain new and useful Improvements in Circuit-Closing Attachments for Pressure-Gages, of which the following is a specification.

My invention relates to certain appliances designed to be employed in connection with apparatus responding to variations in pressure, and especially to variations of high pressure, for the purpose of controlling the connections of electric circuits.

The special object of the inventionis to provide convenient means for causing a current of one polarity or the other to be sent over a main line accordingly as a pressure exceeds or falls below predetermined limits.

The invention consists in applying to the dial of a suitable pressuregage-forinstance, to an ordinary form of steam-gagc-two pairs of adjustable contact-arms which are electric ally connected with a battery, and in applying to the moving shaft carrying theindicator two insulated circuit-closing arms designed to make contact with one pair or the other of the contact-arms accordingly as the pressure exceeds or falls below the predetermined limits. By making contact with one pair a current of a given polarity is sent to line, and by making contact with the other pair a current of opposite polarity is sent.

In the acconuganying drawings, Figure 1 is a plan view, partly in section, illustrating the invention, and Fig. 2 is a transverse section of the same.

Referring to the figures, E represents a steam-gage of any suitable character and of well-known construction. The arbor p of this gage carries, instead of the usual form of indicator, two insulated index-arms, a anda These arms are carried upon a block, a, of insulatin g materiahwhich is attached to a sleeve, 0, fitting tightly upon the arbor. The arm a is designed to be connected by an electric conductor, 2, with a binding-screw, C, which in turn is connected with a main line, L. The arm a is in electrical connection with the sleeve 0, and thus with the frame of the instrument, which carries a binding-screw, B.

(No modcl This binding-screw is connected with the earth by a conductor, 7.

Upon the arm a there is carried a contact, p, and upon the arm n a corresponding contact, 1). These contacts are respectively designed to make electrical connection with corresponding contacts, 1) and :1) and p and p. The contacts p and p are carried near the respective ends of a resilient arm, 8, and the contacts p and p" are carried upon a similar arm, 5, both of which are secured to an adjustable collar, S, of insulating material, carried upon asupport or plate, H, whieh surrounds the arbor It is movable in either direction, so that the position of the contacts 12'' and p, as well as the contacts f and p, is adjustable with reference to the dial of the gage. The spring 3, and thus the contacts 1) and p", are connected by a conductor, 1, with a binding-post, A, which is in electrical connection through conductor 5 with one pole-say the p0sitiveof a battery, R. The spring sis connected by a conductor, 3, with a bindingpost, D, and through a conductor, 4, with the negatit e pole of the battery It will be understood from the foregoing that if the pressure changes sui'ticiently to revolve the arbor p until 1) strikes 1) and p strikes 1) a circuit will be completed from the positive pole of the battery through the conductors 5 and lto the spring 8, thence through the contacts 19 and p, arm a, the conductor 2 to the binding-post C, and thence to the line L. The negative pole of the battery will at the same time be connected through the con ductors a and 3 with the spring 3, and thence through the contacts 1) and p with the arm a", and thence through the frame of the instrument to binding'post B, and thence through conductor 7 to the earth. A positive current will thus be transmitted. If, on the otherhand, the arbor p be moved in the opposite direction and the contacts 1) and p make contact with the contacts 1) and 1), respectively, then the circuit will be completed from the negative pole of the battery through the conductors 4 and 3 to the spring 5 thence through the contacts p and p to the arm n, and thus with the line, as before,while the positive pole will be connected through the conductors 5 and 1 with the spring .9, and through the contacts 1) and 12 with the arm n", and thus to the earth. A negative current will thus be sent to line. For the purpose of adjusting the limits between which the pressure-gage may move without causing acircuit to be thus completed, there is preferably attached to the arm 8 near one end a threaded rod, t, extending through a corresponding opening in the arm 8 A nut, t turning upon this rod, is employed for adj usting the ends of the spring carrying the contacts 12 and 12 more closely to each other against their resilience, which tends to separate them. A similar rod, 25 is attached near the opposite end of the spring 5 This rod extends through an opening in the spring .9, and an adjusting-nut, t, is applied to it for a similar purpose.

It is desirable that, although the device should operate to close the circuits in the manner described the movement of the indicator should not be arrested. For this purpose the contacts 1) and 19 carried upon the arms a and a are constructed to touch against the corresponding contacts, completing circuits therethrough, but to be capable of passing over them freely should the variation in pressure continue. For this purpose they are preferably constructed to curve upward at their ends slightly, and the resilience of the arms a and n permits them to yield sufficiently to pass.

I claim as my invention 1. The combination,substantially as hereinbefore set forth, with a pressure-gage, of two insulated circuit-closing arms, two pairs of contact-arms respectively applied thereto, conductors connecting one of the circuit-closing arms with the earth and the other with a main line, and conductors connectingone contact-arm of each pair with one pole of a battery and the remaining contact'arms with the other pole.

2. The combination, substantially as hereinbefore set forth, with a pressure-gage, of two insulated circuit-closing arms moving therewith, two insulated contact-arms, the ends of which respectively extend upon opposite sides of the circuit-closing arms, and means for adjusting the positions of said contact-arms with reference to the circuit-closing arms.

3. The combination, substantially as hereinbefore set forth,with a pressure-gage, of two circuit-closing arms, contact-arms extending upon opposite sides of each, and means for adjusting the separation from each other of the contactarms applied to each circuit-closing arm.

4. The combination, substantially as hereinbefore set forth, with a pressure-gage, of two circuit-closing arms respectively connected with the earth and a main line, two contactarms applied to each circuit-closing arm, a battery-having one pole connected with one of the contact-arms applied to each circuitclosing arm and the other pole applied to the 5 remaining contact-arms, and means for adj usting the positions of said contact-arms with reference to the other and to the corresponding circuit-closing arm.

5. The combination, substantially as hereinbefore set forth, with a pressure-gage, of the insulated contacts 12 and 19 the flexible contact-arms s and s", carrying the contacts p p and p p, the adjusting-rods t and t and the adjustable support for said contact-arms.

In testimony whereof I have hereunto subscribed my name this 1st day of December, A.

MILTOh W. GROVESTEEN.

Witnesses:

CAROLINE E. DAVIDSON, CHARLE$ A. TERRY. 

